Mercaptans production



Jan. 19, R, CI MERCAPTANS PRODUCTION Filed Dec. 14', 1962 f LA,

, estates Fat-:sented dan. 19, 1955 3,165,500 MERCAPTANS PREUCHN RalphC. Sole, Bartlesville, Sida., assigner to Phillips Petroleum Qompany, acorporation of Delaware Filed Dec. 1e, 1962, Ser. No. 244,700 2 Claims.(Cl. Zeil-new) This invention relates to a-process for the production oftertiary butyl mercaptans. More particularly, this invention relates toa method for producing tertiary butyl mercaptans from tertiary octylmercaptans. In one aspect this invention relates to a process forimproving the economics of a tertiary dodecyl mercaptan system byconvert-ing by-product tertiary octyl mercaptan to a lower molecularweight compound.

` the total tertiary butylfmercaptan to be combined and In theproduction of tertiary dodecyl mercaptan from triisobutylene andhydrogen sulfide, a tertiary octyl mercaptan by-product is obtained. lWhile this oy-product is useful, lower molecular weight mercaptans aredesirable vfor many purposes. `Thus a method for-converting the highermolecular weight tertiary mercaptans such as tertiary octyl mercaptansto a lower molecular weight tertiary mercaptan such as tertiary butylmercaptan would be of significant Value. For example, a method ofproviding other saleable products from by-product material would addsignificantly to the economics of the overall Y process from which theby-product initially was obtained. Therefore it is an object of thisinvention to provide a method for the production of lower molecularweight mercaptans from higher molecular weight mercaptans.

Another object of this invention is to provide a process for theconversion of tertiary octyl mercaptans to tertiaryy butyl mercaptans. K

Other objects, aspects and the several advantages of this invention willbe apparent to those skilled in the art 1 from the following discussion,the claims, and the drawing, which is a schematic view of the process ofthe invention.

In accordance with this invention, I have discovered that highermolecular weight tertiary mercaptans can be readily converted to lowermolecular weight tertiary mercaptans by treating same with hydrogensulde in the presence of a suitable catalyst. More particularly, bysubjecting tertiary octyl mercaptans to the action of hydrogen sulfidein the presence of a Filtrol catalyst there is obtained substantialconversion to the tertiary butyl mercaptan.

The process of this invention can further be illustrated by referenceyto the accompanying drawing which represents in schematic form anarrangement of apparatus suitable for carrying out the invention. Y Inone embodiment, triisobutylene is introduced by way of conduit 10 toreactor A, 13. Filtrol catalyst is introduced by way of conduit 12 andhydrogen, sulfide is provided by way of conduit 11 communicating withthe reactor 13. Reactor 13 is maintained at about 900 p.s.i.g. at 75 to86 F. and the resulting reaction mass is passed by means of conduit 14to separation zone 15 from which tertiary dodecyl mercaptan is removedby way of conduit 16. Any tertiary butyl mercaptan produced during thereaction is removed by means of conduit 17. which cornmunicates withconduit 27. Unreacted triisobu-tylene can be removed by way ofconduit-18 and returned through conduit 24 to reactor13 as recycle. VThetertiary octyl mercaptan by-product ofthe reaction is passed by way ofconduit 19 to reactor B, 20, wherein additional catalyst is provided bymeans ofA conduit 22 and additional hydrogen The resulting mercaptanlisrei y sulde is supplied by meansV of conduit'Zl. The reactor f 20 ismaintained at a pressure vof about 800` p.s.'i.g. atV 300 v to 400 F; toconvert' the tertiary octyl mercaptan to ter- 1 tiary butyl mercaptan.

kmoved from reactor 20`by means of conduit 23. Conduit 17 communicatingwith conduit 27 provides a means for additionally heated. Tertiary octylmercaptanwhen desired can be removed by means of conduit 25, thusallowing only that amount excessive to the current needsy to beconverted to tertiary butyl mercaptan in accordance with this invention.The reactor ellluent is passed to separationrzone wherein the desiredtertiary butyl mercaptan is separated and removed by way of conduit 27.Unreacted 0 tertiary octyl mercaptan is recycled by way of conduit 26 toreactor 2,0 for additional treatment.

The following example will further illustrate the invention. v

` Example A 200 ml. jacketed catalyst case equipped with a thermowelland heater was supplied with Filtrol Grade V7l catalyst activated at 400F. in a stream of air prior to use. Tertiary octyl mercaptan to be usedhada boiling range of between 280 and 330 F. and was removed vfrom thesystem for ymanufacture of tertiary dodecyl mercaptan. The tertiaryoctyl mercaptan had the following composition by chromatograph.

Component: f Weight percent Tertiary butyl mercaptan TraceDiisobutylenes 0.5l Di-tertiary butyl sulde 4.5

' Triisobutylene i 5.5 Tertiary octyl mercaptan 89.5

Hydrogen sulfide and ,the tertiary octyl rnercaptan` produced asby-product in the production of tertiary dodecyl mercaptan were added ina 2:1 mol ratio to a reactor at a constant rate. A pressure controlleron the case outlet of the reactor maintained the pressure on the system.

Temperatures between 300 and 400 F. were employed,

a reactor temperature of about 350 F. being preferred. A pressure withinthe range of about 700 to 850 p.s.i.g. was maintained, about 800p.s.i.U. being preferred. The resulting tertiary butyl mercaptan cutwhen distilled, from the composite eflluent from the reactor gave aproduct with a mercaptan purity, weight percent, of 95.3 (mercaptanpurity determined by mercaptan sulfur analysis). The tertiary butylmercaptan content of the effluent was 40.2 weight percent. The-tertiaryoctyl mercaptan content from the Vreactor was recycled at 350 F. and 800p.s.i.g. over the same catalyst and upon subsequent sepmation of theeffluent from the recycle operation gave about 22.2 weight percenttertiary butyl mercaptan.V

As indicated by the above example, tertiary butylmercaptan can be,produced in good yield from tertiary octyl mercaptan. VFiltrol catalystis active for the reaction, giving conversions as high as 40 percent perpass for fresh feed and 24 percent for recyclefeed.

The term Filtrol catalyst as employed herein is inclusive of the groupof acid-activated adsorption contact catalyst made from relatively purecrystals of montmorillonite (Mg, Ca)OAl2O35SiO2-nH2O. Such catalyst maybe used either with liquids orwith gases in either pellet or powderform.

Reasonable variations and modifications are possible within the scope ofthe foregoing disclosure without de- K parting from the spirit or scopethereof.

I claim: p l 1. A process for forming tertiary butyl mercaptans fromtertiary octyl mercaptans which comprises reacting said I tertiary octylmercaptans with hydrogen sulfide at a temperature within the range ofabout. 300 Vto 400 F. and a pressure Within the range of about 700 to850 p.s.i.g. in theV presence of an acid activated montmorilloniteabsorption contact catalyst.

No.- references cited.

2f. The process of claim 1 wherein the ltemperature is Y about 350 F.and the pressure is about S00 psig.. I,

1. A PROCESS FOR FORMING TERTIARY BUTYL MERCAPTANS FROM TERTIARY OCTYLMERCAPTANS WHICH COMPRISES REACTING SAID TERTIARY WITHIN THE RANGE OFABOUT 300* TO 400*F. AND PERATURE WITHIN THE RANGE OF ABOUT 300* TO400*F. AND A PRESENCE WITHIN THE RANGE OF ABOUT 700 TO 850 P.S.I.G INTHE PRESENCE OF AN ACID ACTIVATED MONTMORILLONITE ABSORPTION CONTACTCATAYLST.